Oki OKIOFFICE 84, Service Manual

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Service Guide OKIOFFICE 84
Chapter A Board Descriptions
A3.1.12 R51 Circuit Diagram (Page 12/12)
1. Block diagram
The circuit diagram consists of the following connector:
• Connector CN6 that provides an interface between R51 board and power supply unit.
2. Function
1) Sensor and switch control
Five types of sensors are used in the printer as listed below. All of their output enter IOGA ports for referring to and
processing by the CPU.
Figure A3.1.15 shows sensors and switch control.
Inlet sensor 1
l
Write sensor (To detect the paper top position for printing)
l
Outlet sensor
l
Toner end sensor
l
Cover status switch
l
The functions of various sensors are described in the following table.
Sensor Type Sensor Name Function
PSIN1-N Inlet sensor 1 This photosensor is positioned before the
resist roller to detect whether the paper
has entered into the printer section.
WRSNS-N Write sensor Detects the arrival of paper at designated
position on the paper transport route
inside the printer in order to turn on the light of
the LED head.
0: Paper exists, 1: Paper does not exist
PSOUT-N Outlet sensor Located at the exit of the printer to supervise
the paper exit operation.
0: Paper exists, 1: Paper does not exist
TNRSNS-N Toner sensor Detects the remaining toner in the toner
cartridge.
"The length of time of low-toner state within
fixed time interval" detects a
low-toner state.
CVOPN-N Cover open
sensor
. Detects whether the cover of the printer
section is open or not